Method for manufacturing bulletproof fabric

ABSTRACT

Disclosed is a method for manufacturing bulletproof fabric, the method comprising weaving fabric; scouring the fabric; applying a pretreatment process to the scoured fabric; and applying a water-repellent process to the pretreated fabric, wherein the pretreatment process comprises adjusting a moisture regain of the scoured fabric. In this method, the fabric is treated with the pretreatment process before the water-repellent process, so that it is possible to maintain the constant concentration of water-repellent composition, and to permeate the water-repellent agent into the fabric with easiness, thereby producing the bulletproof fabric with the uniform and good water-repellent property. Thus, even though the bulletproof fabric is used for a long period of time, it is possible to prevent deterioration of the bulletproof property in the fabric.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for manufacturing bulletproof fabric, and more particularly, to a method for manufacturing bulletproof fabric with uniform and good water-repellent property.

2. Discussion of the Related Art

Generally, bulletproof fabric has been widely used for various bulletproof products, for example, body armor, bulletproof helmet, bulletproof panel, and etc. The bulletproof products are capable of protecting the wearer's body from splinters of projectile. A bulletproof function of the bulletproof products largely depends on a bulletproof function of the bulletproof fabric.

Related art bulletproof fabric can be manufactured by weaving fabric through the use of nylon or aramid yarns, and treating the prepared fabric with scouring and water-repellent process.

Through the scouring process using a predetermined scouring agent, oil or foreign materials are removed from the fabric. Also, the water-repellent process is to prevent ambient moisture from being absorbed into the fabric by permeating a predetermined water-repellent agent into the fabric.

If the bulletproof fabric absorbs the moisture for a long period of time, properties of the fabric may be deteriorated, that is, bulletproof properties of the fabric may be deteriorated. In this respect, the water-repellent process is carried out so as to prevent deterioration of the bulletproof property by minimizing the moisture absorption in the fabric. However, if the fabric is contaminated with the oil or foreign materials, it is difficult to smoothly carry out the water-repellent process for permeating the water-repellent agent into the fabric. Thus, the fabric is treated with the scouring process before the water-repellent process. That is, the oil or foreign materials have to be completely removed from the fabric through the scouring process, which enables to carry out the water-repellent process smoothly.

The water-repellent process is carried out subsequent to the scouring process for removing the oil or foreign materials from the fabric.

However, if the water-repellent process is carried out without a drying process after the aforementioned scouring process, a concentration of composition with the water-repellent agent might be gradually diluted with water of the scoured fabric, to thereby deteriorate water-repellent property.

Also, if the water-repellent process is applied to fabric with a rigid molecular structure, for example, aramid fabric, the water-repellent agent cannot permeate into the inside of the fabric. That is, the water-repellent agent is apt to adhere only to the surface of the fabric. Under such circumstance, if the fabric is used for a long period of time, the water-repellent property of the fabric is deteriorated gradually.

According as the water-repellent property of the fabric is deteriorated, the moisture is easily absorbed into the bulletproof fabric, thereby lowering the bulletproof property.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a method for manufacturing bulletproof fabric that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.

An advantage of the present invention is to provide a method for manufacturing bulletproof fabric, which is treated with a pretreatment process before a water-repellent process for scoured fabric, to realize uniform and good water-repellent property.

Additional features and aspects of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, there is provided a method for manufacturing bulletproof fabric comprising: weaving fabric; scouring the fabric; applying a pretreatment process to the scoured fabric; and applying a water-repellent process to the pretreated fabric, wherein the pretreatment process comprises adjusting a moisture regain of the scoured fabric.

At this time, the moisture regain of the fabric is 0.1˜3% after the process of adjusting the moisture regain of the scoured fabric.

Also, the pretreatment process comprises a flattening process to flatten the scoured fabric by applying a tension in right and left directions.

Both the pretreatment process and the water-repellent process are carried out in the same apparatus.

Further, a temperature of the fabric just before the water-repellent process is maintained at 50% or more of a temperature of the fabric just after the pretreatment process, so as to enable an easy permeation of water-repellent agent into the fabric.

The pretreatment process is carried out at 90˜190° C.

The pretreatment process is carried out under the circumstance that the fabric moves at 6˜50 mpm.

The water-repellent process comprises a heat treatment for heating the fabric at 120˜200° C. for 15˜150 seconds.

The process of weaving the fabric comprises weaving aromatic polyamide multifilament as warp and weft in a plain or basket type.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

In the drawings:

FIG. 1 illustrates a fabric scouring process according to one embodiment of the present invention;

FIG. 2 illustrates a fabric scouring process according to another embodiment of the present invention;

FIG. 3 illustrates a fabric scouring process according to another embodiment of the present invention; and

FIG. 4 illustrates a fabric water-repelling process according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Reference will now be made in detail to an embodiment of the present invention, example of which is illustrated in the accompanying drawings.

Hereinafter, a method for manufacturing bulletproof fabric according to the present invention will be described with reference to the accompanying drawings.

A method for manufacturing bulletproof fabric includes preparing yarns; preparing fabric with warp and weft using the prepared yarns; scouring the prepared fabric; applying a pretreatment process to the scoured fabric before a water-repellent process; and applying the water-repellent process to the pretreated fabric. These steps will be sequentially described as follows.

First, the process of preparing yarns will be described in detail.

The process of preparing yarns comprises preparing aromatic polyamide multifilament. Herein, the process of preparing aromatic polyamide multifilament may include steps of preparing aromatic polyamide polymer by polymerizing aromatic diamine with aromatic diacidchloride in a polymerization solvent; preparing a spinning dope by dissolving the aromatic polyamide polymer in a concentrated sulfuric acid solution; and preparing a filament by spinning the spinning dope through the use of spinneret, and coagulating the spinning dope.

The aromatic polyamide multifilament may comprise 400˜1,000 monofilaments, wherein each monofilament has 0.7˜1.6 deniers. If the monofilament is not more than 1.6 deniers, the number of monofilaments used for preparing the multifilament having the desired predetermined fineness is increased so that impact-absorbing capability of the prepared fabric is improved. Meanwhile, the monofilament whose fineness is less than 0.7 deniers may cause poor weavability.

When a tenacity of the aromatic polyamide multifilament is not less than 22 g/d, the fabric prepared by the aromatic polyamide multifilament is profitable to a bulletproof property. However, the fineness and number of the aromatic polyamide monofilaments and the tenacity of the aromatic polyamide multifilament are not limited to the aforementioned ranges.

The process of preparing the fabric comprises preparing the fabric by weaving the aromatic polyamide multifilament as warp and weft of a plain or basket type. In this case, when each of warp density and weft density is 5˜15 yarns/cm, and the prepared fabric has 5,000˜18,000N/5 cm tenacity, the bulletproof property can be improved. However, the tenacity of the fabric, the warp density, and the weft density are not limited to the aforementioned ranges.

The process of scouring the fabric is to remove oil or foreign materials from the aromatic polyamide multifilament for the fabric. If only the water-repellent process is applied to the fabric without the scouring process, it is difficult to smoothly carry out the water-repellent process.

The process of scouring the fabric comprises submerging the fabric into a scouring bath filled with a composition including a scouring agent therein. In this case, the composition comprises surfactant of 0.2˜10 g/L concentration, and scouring agent of 0.2˜15 g/L concentration. The scouring agent may comprise at least one of sodium hydroxide (NaOH), sodium carbonate (Na₂CO₃), and their mixture.

At this time, sodium hydroxide (NaOH) or sodium carbonate (Na₂CO₃) is a main component for removal of the oil or foreign materials. If the concentration of the scouring agent is less than 0.2 g/L, it is difficult to completely remove the oil or foreign materials from the fabric. Meanwhile, if the concentration of the scouring agent is more than 15 g/L, the fabric property is deteriorated so that strength of the fabric is lowered.

The surfactant uniformly disperses the scouring agent in the fabric. The surfactant may comprise at least one of anion surfactant and non-ion surfactant. In this case, if a concentration of the surfactant is less than 0.2 g/L, it is difficult to effectively remove the oil or foreign materials from the fabric due to lowering of dispersion. Meanwhile, if a concentration of the surfactant is more than 10 g/L, the fabric property is lowered so that strength of the fabric is lowered.

The anion surfactant may be sodium dodecylbenzene sulfonate, sodium polyoxyethylene alkyl phenyl ether sulfate, or alkylbezene sulfonate.

The non-ion surfactant may be polyoxyethylene nonylphenol ether, polyoxyethylene tridecyl ether, polyoxyethylene octylphenol ether, or ethoxylated alcohol.

The scouring process according to the present invention may be carried out in various methods.

First, the scouring treatment according to one embodiment of the present invention may be carried out in the following method of FIG. 1.

As shown in FIG. 1, a scouring apparatus according to one embodiment of the present invention includes plural scouring baths 110, plural cleaning baths 120, and first to third rollers 130 a, 130 b, and 130 c. The plural scouring baths 110 and cleaning baths 120 are arranged in line, wherein each scouring bath 110 is filled with a scouring-agent composition 115, and each cleaning bath 120 is filled with a cleaning solution 125. The first roller 130 a is provided between each scouring bath 110 and each cleaning bath 120. The second and third rollers 130 b and 130 c are provided in each of the plural scouring baths 110 and cleaning baths 120. At this time, the second roller 130 b is positioned at a lower part of each of the scouring bath 110 and cleaning bath 120; and the third roller 130 c is positioned at an upper part of each of the scouring bath 110 and cleaning bath 120. Due to the long scouring bath 110 and cleaning bath 120, the fabric might droop while being moved in the scouring bath 110 and cleaning bath 120. In order to prevent the fabric from drooping for the movement in the scouring bath 110 and cleaning bath 120, the second and third rollers 130 b and 130 c are positioned in the different heights. FIG. 1 discloses the two scouring baths 110 and the two cleaning baths 120, but it is not limited to this structure. That is, the number of first, second and third rollers 130 a, 130 b and 130 c may be changeable.

If using the scouring apparatus with the aforementioned structure, the fabric moves to the cleaning bath 120 through the scouring bath 110 while being wound on the first, second and third rollers 130 a, 130 b and 130 c, to thereby scour the fabric. A moving speed of the fabric may be set at 10˜30 mpm.

Between the steps of submerging the fabric into the scouring bath 110 and cleaning the fabric, there may be an additional step of neutralizing the fabric. This neutralizing step is not a necessity. However, if the aforementioned scouring agent uses the strong alkaline sodium hydroxide, it is preferable to carry out the neutralizing process using a small amount of acetic acid (CH₃COOH).

The scouring process according to another embodiment of the present invention may be carried out in the following method of FIG. 2.

The process of scouring the fabric comprises submerging the fabric into a container 210, wherein the container 210 functions as the scouring bath containing the scouring-agent composition. This step of submerging the fabric into the container 210 may be repetitively carried out with the gradually-increased temperatures. That is, the fabric may be firstly submerged into the container 210 maintained at 55˜65° C.; secondly submerged into the container 210 maintained at 65˜75° C.; and thirdly submerged into the container 210 maintained at 85˜95° C. Also, the submerging process may be repetitively carried out at each temperature. For example, the first submerging process of 55˜65° C. is carried out 2˜6 times; the second submerging process of 65˜75° C. is carried out 2˜6 times; and the third submerging process of 85˜95° C. is carried out 2˜6 times.

The process of submerging the fabric into the scouring bath may be performed through the use of apparatus shown in FIG. 2. That is, as shown in FIG. 2, the process of submerging the fabric may be performed through the use of apparatus which includes a container 210 filled with a solution 220 corresponding a scouring-agent composition; first and second take-up rollers 230 a and 230 b positioned outside the container 210; and a guide roller 240 positioned inside the container 210.

In more detail, the container 210 filled with the solution 220 is prepared as the scouring bath containing the aforementioned scouring-agent composition, and then the fabric is wound on the first take-up roller 230, second take-up roller 230 b, and guide roller 240. After that, the fabric unwound from the first take-up roller 230 a is submerged into the scouring bath by the guide roller 240, and is then wound on the second take-up roller 230 b. Thus, the fabric wound on the first take-up roller 230 a is unwounded therefrom, and is then wound on the second take-up roller 230 b through the guide roller 240, to thereby complete the submerging process one time. Thereafter, the fabric wounded on the second take-up roller 230 b is unwounded therefrom; submerged into the scouring bath by the guide roller 240; and then wound on the first take-up roller 230 a, to thereby complete the submerging process two times. Thus, the submerging process may be repetitively performed through the use of apparatus shown in FIG. 2. If the temperature of the scouring bath is raised to the aforementioned range, the submerging process can be repetitively performed at various temperatures, through the use of apparatus shown in FIG. 2.

After the process of submerging the fabric into the scouring bath, the fabric is submerged into the first cleaning bath, to thereby carry out the first cleaning process. The first cleaning process is carried out 2˜10 times, wherein the first cleaning bath is maintained at 55˜65° C. The first cleaning bath may use the container 210 shown in FIG. 2. At this time, the cleaning solution of the first cleaning bath may be water.

After the first cleaning process, the fabric is submerged into a neutralizing bath filled with a neutralizing solution, to thereby neutralize the fabric. Then, the fabric is submerged into the second cleaning bath, to thereby clean the fabric secondly. These steps of neutralizing and secondly cleaning the fabric are not a necessity. However, if the aforementioned scouring agent uses the strong alkaline sodium hydroxide, it is preferable to carry out the steps of neutralizing and secondly cleaning the fabric.

The neutralizing process may be carried out 2˜4 times under the circumstance that the neutralizing bath is maintained at 55˜65° C., and the second cleaning process may be carried out 2˜4 times under the circumstance that the second cleaning bath is maintained at 55˜65° C. Both the neutralizing process and the second cleaning process may use the container 210 shown in FIG. 2. At this time, the neutralizing agent filled in the neutralizing bath may use a small amount of acetic acid, and the cleaning agent filled in the second cleaning bath may be water.

The scouring process may be carried out by a cold pad batch (CPB) method according to another embodiment of the present invention.

The scouring process may comprise submerging the fabric into the scouring bath filled with the scouring-agent composition; aging the fabric for a predetermined time period; and cleaning the fabric by submerging the fabric into the at least one cleaning bath.

As shown in FIG. 3, the scouring process may comprise unwinding the fabric from a drawing-out roller 310; submerging the unwound fabric into a scouring bath 320 by a guide roller; pressing the fabric through the use of mangle roller 330 to make a constant content of scouring-agent composition and to permeate the scouring-agent composition into the inside of the fabric; and winding the fabric on a winding roller 340. At this time, a temperature of the scouring bath 320 is maintained at 30˜50° C.

After completing the process of submerging the fabric into the scouring bath 320, the fabric may be kept in an aging container for 10˜24 hours, wherein a temperature of the aging container may be maintained at 30˜50° C. When keeping the fabric in the aging container, the fabric may be rotated at 20˜70 rpm, whereby the scouring-agent composition may be uniformly permeated into the entire fabric.

As shown in FIG. 1, the process of cleaning the fabric by submerging the fabric into the cleaning bath may be carried out by sequentially submerging the fabric into the plural cleaning baths 120, that is, 2˜10 cleaning baths 120. Under the circumstance that the plural cleaning baths 120 filled with the cleaning solution such as water are arranged in line, the fabric is cleaned through the sequential movement from the first to final cleaning baths 120. At this time, rollers are respectively positioned between each of the plural cleaning baths 120, and simultaneously inside each cleaning bath 120, which enables the sequential movement of the fabric. If the cleaning bath 120 is long, the plural rollers are provided inside the cleaning bath 120, to thereby prevent the fabric from drooping inside the cleaning bath 120.

The first cleaning bath may be maintained at 85˜95° C., and the remaining cleaning baths may be maintained at 75˜85° C. At this time, the temperature of the first cleaning bath is 10° C. higher than the temperature of the remaining cleaning baths.

When the fabric is submerged into the plural cleaning baths, the first cleaning bath has the highest concentration; and the concentration is gradually lowered as going from the second to final cleaning baths. This is because the amount of materials extracted from the fabric to the cleaning bath for the cleaning process is gradually decreased with the progress of the cleaning process. With the progress of the cleaning process, the concentration is gradually changed among the plural cleaning baths. As the cleaning solution overflows from the final cleaning bath toward the first cleaning bath, it is possible to minimize the concentration difference among the plural cleaning baths.

When the scouring-agent composition is formed of the strong alkaline sodium hydroxide, the process of neutralizing the fabric by submerging the fabric into the neutralizing bath is carried out before cleaning the fabric, wherein a small amount of acetic acid (CH₃COOH) may be used as the neutralizing agent.

Then, the water-repellent process will be explained as follows.

After completing the removal of oil or foreign materials from the fabric through the aforementioned scouring process, the water-repellent process is carried out by submerging the fabric into a water-repellent agent, and applying a heat treatment thereto.

However, the scoured fabric contains a large amount of water therein. Especially, a moisture regain of aramid fabric is about 7%. Thus, if the aramid fabric is kept in the external for a long period of time even after the scouring and drying processes, the moisture regain of aramid fabric becomes about 7%. If the scoured fabric with the large amount of water therein is continuously submerged into a water-repellent composition, the water contained in the scoured fabric is continuously supplied to the water-repellent composition, whereby a concentration of the water-repellent agent is gradually lowered. Accordingly, if the water-repellent process is carried out for a long period of time, the concentration of the water-repellent composition is lowered largely in comparison to its initial concentration, to thereby cause deterioration in water-repellent property of the produced fabric.

Also, a non-water-soluble repellent agent is different in its property from the water. If the fabric contains a large amount of water therein, the water contained in the fabric prevents the permeation of water-repellent agent into the fabric, whereby the produced fabric has the poor water-repellent property.

Before the water-repellent process, the pretreatment process is applied to the scoured fabric, to thereby adjust the moisture regain of the fabric to a predetermined range. Accordingly, it is possible to prevent a dilution of the water-repellent composition, and simultaneously to help the smooth permeation of water-repellent agent into the fabric, to thereby obtain the fabric with the uniform and great water-repellent property.

The moisture regain of the fabric scoured through the pretreatment process is adjusted to 0.1˜3%, preferably. If the moisture regain of the fabric is less than 0.1% by the pretreatment process, the fabric may be easily overheated so that the bulletproof property of the fabric may be deteriorated. Meanwhile, if the moisture regain of the fabric is more than 3% by the pretreatment process, it is difficult to uniformly dry the fabric, that is, it is difficult to obtain the fabric with the uniform water-repellent property due to the serious moisture-regain deviation in the fabric.

A flattening process is carried out by applying a tension in right and left directions to the scoured fabric for the pretreatment process, to thereby adjust the moisture regain of the fabric. The tension may be applied by stretching the fabric under the circumstance that both ends of the scoured fabric are held through the use of pins or clips. Preferably, the tension is adjusted to keep a density of fabric at 95% or more in comparison to a density of the fabric before the pretreatment process. If the tension is excessively applied for the flattening process, the density of fabric is less than 95%, to thereby deteriorate the bulletproof property.

If a heat is applied to the fabric under the circumstance that the tension in right and left directions is applied to the fabric, the fabric is flattened. Thus, the water-repellent agent can be uniformly permeated into the entire fabric for the water-repellent process.

Both the pretreatment process and the water-repellent process may be carried out in the same apparatus. If the pretreatment process and the water-repellent process are carried out in the different apparatuses, it may cause the complicated process and the increased production cost. In addition, the moisture regain of the fabric may vary according to the fabric-kept time, place, and season, so that it is difficult to produce the bulletproof fabric with the uniform water-repellent property.

The pretreatment process and the water-repellent process may be carried out in sequence. A temperature of the fabric just before the water-repellent process is maintained at 50% of a temperature of the fabric just after the pretreatment process, preferably. Since a structural property of the water-repellent agent is different from a structural property of the fabric, the permeation of water-repellent agent into the fabric becomes difficult. Especially, in case of the aramid fabric having a rigid molecular structure, the permeation of water-repellent agent into the fabric becomes more difficult.

The water-repellent process is applied when the fabric is cooled to be at least 50% of the temperature measured in the heated fabric. In this case, mobility of the molecular chain is improved so that a permeation speed of the water-repellent agent is increased, to thereby improve the water-repellent property of the fabric.

For maintaining the aforementioned temperature of the fabric, the water-repellent process is carried out just after the pretreatment process without the cooling of the fabric.

The pretreatment process and the water-repellent process may be simultaneously carried out as shown in FIG. 4. That is, as shown in FIG. 4, the pretreatment process and the water-repellent process may be carried out through the use of apparatus comprising a supplying roller 410 on which the scoured fabric is wound, a pretreatment part 420 for applying the heat to the fabric so as to maintain the constant moisture-regain of the fabric, a water-repellent part 430 for applying the water-repellent process, and a winding part 440 for winding the fabric treated with the water-repellent process.

The pretreatment part 420 comprises plural upper guide rollers 421 a, 421 b, 421 c, and 421 d; and plural lower guide rollers 422 a, 422 b, 422 c, and 422 d, which help the smooth movement of the fabric. Also, the water-repellent part 430 may comprise a water-repellent bath 431 filled with a water-repellent composition; a padding roller 432 for maintaining a constant content of the water-repellent composition in the fabric; and a heat-treatment part 433 for adhering the water-repellent agent to the fabric.

For the pretreatment process, the fabric moves at 6˜50 mpm under the circumstance that the fabric is heated at 90˜190° C., preferably.

If the temperature of the pretreatment process is less than 90° C., or the movement speed of the fabric is more than 50 mpm, the moisture regain of the fabric is not uniform so that the water-repellent property of the fabric might be deteriorated. Meanwhile, if the temperature of the pretreatment process is more than 190° C., or the movement speed of the fabric is less than 6 mpm, the fabric is overheated so that the bulletproof property of the fabric might be deteriorated.

The pretreatment process may use a vertical type apparatus shown in FIG. 4, or may use a horizontal type apparatus.

The pretreatment process may comprise the flattening process to apply the tension in right and left directions to the scoured fabric, wherein the tension in right and left directions may be applied according to various methods. For example, the tension may be applied by stretching the fabric under the circumstance that both ends of the scoured fabric are held through the use of guide rollers, pins, or clips.

After the pretreatment process, the water-repellent process is applied to the fabric in the water-repellent part 430. As shown in FIG. 4, the water-repellent part 430 may comprise the water-repellent bath 431, the padding roller 432, and the heat-treatment part 433.

The water-repellent bath 431 is filled with the water-repellent composition; the padding roller 432 is provided to maintain the constant content of the water-repellent composition in the fabric; and the heat-treatment part 433 is provided for adherence of the water-repellent agent to the fabric.

The water-repellent agent may be produced by adding 0.1˜1 wt % silicon oil and 0.5˜10 wt % isopropylalcohol on the basis of 100 parts by weight of 1˜5 wt % aqueous solution of the composition comprising 25˜35 wt % hydroxylated perfluoroalkylethyl acrylate copolymer, 10˜15 wt % dipropylene glycol, and 50˜65 wt % water.

The hydroxylated perfluoroalkylethyl acrylate copolymer allows the water-repellent property of the fabric. If it is added to be less than 25 wt %, it is difficult to obtain the desired water-repellent property of the fabric. Meanwhile, if it is added to be more than 35 wt %, the fabric has inferior softness while there is no remarkable increase of the water-repellent property in the fabric.

The dipropylene glycol enables to uniformly diffuse the water-repellent components. If it is added to be less than 10 wt %, it is difficult to uniformly diffuse the water-repellent components. Meanwhile, if it is added to be more than 15 wt %, the water-repellent property and softness of the fabric may be deteriorated due to the decrease of components to improve the water-repellent property and softness of the fabric.

If the aqueous solution is less than 1 wt % of the aqueous solution, the water-repellent property may be lowered. Meanwhile, if the aqueous solution is more than 5 wt %, solid components may be excessively adhered to the surface of the fabric, to thereby deteriorate the softness of the fabric.

The silicon oil improves the softness of the fabric, wherein the silicon oil is used in an emulsion type based on Si—O—Si structure. If it is added to be less than 0.1 wt %, it is difficult to obtain the desired water-repellent property of the fabric. Meanwhile, if it is added to be more than 1.0 wt %, the fabric has inferior water-repellent property while there is no remarkable increase of the softness in the fabric.

The isopropylalcohol helps the water-repellent agent to permeate into the fabric with easiness, whereby the water-repellent property and softness of the fabric can be maintained for a long period of time. If it is added to be less than 0.5 wt %, the permeation of the water-repellent agent may be deteriorated somewhat. Meanwhile, if it is added to be more than 10 wt %, the water-repellent property and softness of the fabric may be deteriorated.

The water-repellent composition is prepared by mixing the aforementioned components. Then, the fabric is submerged into the prepared water-repellent composition, whereby the water-repellent composition is impregnated into the fabric. Then, the padding process is applied to maintain the constant content of the water-repellent agent in the fabric, and the heat treatment is applied thereto, to thereby complete the water-repellent process.

The heat treatment is carried out at 120˜200° C. for 15˜150 seconds. At this time, the temperature of the heat treatment is less than 120° C., or the duration of the heat treatment is less than 15 seconds, the water repellent property of the fabric may be deteriorated. Meanwhile, if the temperature of the heat treatment is more than 200° C., or the duration of the heat treatment is more than 150 seconds, the fabric may be damaged.

The bulletproof fabric prepared by the aforementioned process of the present invention can obtain the good water-repellent property, that is, the level 5 of the water-repellent level measured by a spray-testing method.

Also, the bulletproof fabric with the aforementioned properties may be used to produce various bulletproof products, for example, body armor, bulletproof helmet, bulletproof panel, and etc., which may be produced by the generally-known method.

Hereinafter, various embodiments and comparative examples of the present invention will be described as follows. However, the scope of the present invention is not limited to the following various embodiments and comparative examples to be described, which are provided to help your understanding.

First Embodiment

First, fabric of plain type is prepared with aromatic polyamide multifilament obtained by weaving 1,000 aromatic polyamide monofilaments with 1.0 deniers as warp and weft, wherein each of warp density and weft density is 10 yarns/cm.

Then, the prepared fabric is submerged into a scouring bath filled with a scouring-agent composition; wherein the scouring-agent composition comprises 0.2 g/L of sodium hydroxide (NaOH), and 0.2 g/L of ethoxylated-alcohol based non-ion surfactant. Then, the fabric is neutralized through submergence into a neutralizing bath filled with acetic acid (CH₃COOH), and is then cleaned through submergence into a cleaning bath. At this time, the scouring bath is maintained at 85° C., and the cleaning bath is maintained at 75° C.

After that, the scoured fabric is applied with a pretreatment process in the same apparatus. Then, the pretreated fabric is submerged into a composition with a water-repellent agent, and is then squeezed through a padding roller, and heat-treated in sequence, to thereby produce bulletproof fabric.

The pretreatment process is carried out by maintaining the fabric at a moving speed of 120 mpm, and at a temperature of 160° C., under a tension is applied to the fabric, as shown in FIG. 4. The water-repellent agent may be produced by adding and mixing 0.3 wt % silicon oil and 5 wt % isopropylalcohol on the basis of 100 parts by weight of 2.5 wt % aqueous solution of the composition comprising 30 wt % hydroxylated perfluoroalkylethyl acrylate copolymer, 15 wt % dipropylene glycol, and 55 wt % water. The heat treatment is carried out at 200° C. for 25 seconds.

Second Embodiment

A bulletproof fabric is produced in the same process and condition as the aforementioned first embodiment except that a temperature of the pretreatment process is maintained at 100° C.

Third Embodiment

A bulletproof fabric is produced in the same process and condition as the aforementioned first embodiment except that a temperature of the pretreatment process is maintained at 120° C.

Fourth Embodiment

A bulletproof fabric is produced in the same process and condition as the aforementioned first embodiment except that a temperature of the pretreatment process is maintained at 140° C.

Fifth Embodiment

A bulletproof fabric is produced in the same process and condition as the aforementioned first embodiment except that a temperature of the pretreatment process is maintained at 180° C.

First Comparative Example

A bulletproof fabric is produced in the same process and condition as the aforementioned first embodiment except that a water-repellent process is carried out without a pretreatment process.

Second Comparative Example

A bulletproof fabric is produced in the same process and condition as the aforementioned first embodiment except that a temperature of the pretreatment process is maintained at 80° C.

The water-repelling level of the bulletproof fabric according to the aforementioned embodiments and comparative examples can be measured by the following method, which will be shown in the following table 1.

Measuring Water Repellency

First, samples of 250 mm×250 mm are prepared by cutting the bulletproof fabric according to the aforementioned embodiments and comparative examples. Then, water repellency for each sample is measured by a spray method based on ISO 5920:1981. At this time, the water repellency may be classified into the level 5, the level 4, and the level 3, wherein water repellency of the level 5 is not less than 90%, water repellency of the level 4 is not less than 80%, and water repellency of the level 3 is not less than 70%.

TABLE 1 Temperature of pretreat- Water repellency ment process (° C.) (level) Embodiment 1 160 Level 5 Embodiment 2 100 Level 5 Embodiment 3 120 Level 5 Embodiment 4 140 Level 5 Embodiment 5 180 Level 5 Comparative example 1 unapplied Level 3 Comparative example 2 100 Level 4

Accordingly, the fabric is treated with the pretreatment process before the water-repellent process, so that it is possible to maintain the constant concentration of the water-repellent composition, and to permeate the water-repellent agent into the fabric with easiness, thereby producing the bulletproof fabric with the uniform and good water-repellent property. Thus, even though the bulletproof fabric is used for a long period of time, it is possible to prevent deterioration of the bulletproof property in the fabric.

It will be apparent to those skilled in the art that various modifications and variation can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. 

1. A method for manufacturing bulletproof fabric comprising: weaving fabric; scouring the fabric; applying a pretreatment process to the scoured fabric; and applying a water-repellent process to the pretreated fabric, wherein the pretreatment process comprises adjusting a moisture regain of the scoured fabric.
 2. The method according to claim 1, wherein the moisture regain of the fabric is 0.1˜3% after the process of adjusting the moisture regain of the scoured fabric.
 3. The method according to claim 1, wherein the pretreatment process comprises a flattening process to flatten the scoured fabric by applying a tension in right and left directions.
 4. The method according to claim 1, wherein both the pretreatment process and the water-repellent process are carried out in the same apparatus.
 5. The method according to claim 4, wherein a temperature of the fabric just before the water-repellent process is maintained at 50% or more of a temperature of the fabric just after the pretreatment process, so as to enable an easy permeation of water-repellent agent into the fabric.
 6. The method according to claim 1, wherein the pretreatment process is carried out at 90˜190° C.
 7. The method according to claim 1, wherein the pretreatment process is carried out under the circumstance that the fabric moves at 6˜50 mpm.
 8. The method according to claim 1, wherein the water-repellent process comprises a heat treatment for heating the fabric at 120˜200° C. for 15˜150 seconds.
 9. The method according to claim 1, wherein the process of weaving the fabric comprises weaving aromatic polyamide multifilament as warp and weft in a plain or basket type. 